Custom C# script templates sometimes cause the editor to freeze permanently

[macjuul]

Godot version:
3.2 (Mono)

OS/device including version:
Windows 10

Issue description:
When creating a C# script from a custom template (located in script_templates) the editor sometimes permanently freezes and locks up when the .mono directory is present. Some more details gathered after testing:

• The .mono directory generated when opening the project does not cause the freeze
• The freeze always happens after pressing the build button, or running the game
• Deleting the .mono directory does not prevent the crash until the editor is restarted
• Just restarting Godot without deleting .mono does not fix the issue
• No errors/logs in the console

The contents of my script look like this

using Godot;
using System;

namespace Asteroids
{

    public class %CLASS% : %BASE%
    {

        public override void _Ready()
        {
           
        }

        public override void _Process(float delta)
        {
            
        }

    }

}

Steps to reproduce:

• Open up a working Mono project
• Creating a script from a custom template freezes the editor
• Close the editor & delete the .mono directory
• Custom scripts now work again

Minimal reproduction project:
I prefer to keep my projects source private, and so far attempting to reproduce the issue in separate projects hasn't worked out yet

This issue started happening around the same time as my other issue #35664

[KoBeWi]

Can anyone still reproduce this bug in Godot 3.2.3 or any later release?